Counterfeit components and manipulation of electronic control unit coding are two growing problems for automakers. Counterfeiting can result in significant financial loss annually and possible safety risks. Code manipulation (chip tuning) is both a safety and liability issue.

To help control the problem, Infineon Technologies is launching a series of automotive microcontrollers (MCUs) with hardware-based security features, including a protected secret key and encryption engines. Intended for power train and chassis applications, the new devices include a “Secure Hardware Extension” (SHE). The hardware extension addresses security functions described by the “HIS” (Manufacturers’ Software Initiative) Working Group on Security, members of which include Audi, BMW, Daimler, Porsche and Volkswagen.

Infineon Technologies’ new 32-bit AUDO MAX SHE microcontrollers extend the tamper-proofing of electronic control units (ECU) and protect against tuning. AUDO MAX SHE enables auto manufacturers to ensure the integrity of their ECUs and to guard better against exposure to liability claims.

By introducing AUDO MAX SHE, Infineon claims to have a head start over other semiconductor manufacturers in meeting a wish for improved tamper-proofing and anti-theft protection of automotive control units expressed by the HIS Working Group. Security solutions have so far been confined to software level or were coupled with additional external hardware, meaning they were easily circumvented. Infineon offers more than this basic software protection because AUDO MAX SHE monolithically integrates a secure keystore that cannot be read without access authorization. Infineon’s integrated solution has the advantage over the version using external security chips in that the communication does not run via interceptable external bus systems.

In addition, SHE has a cryptographic module that encrypts access codes with up to 128 bits. SHE is complemented by an array of hardware functions which, for example, prevent the application code from being illegitimately read and altered, or identify ECUs in the system network. These are important functions for tamper-proofing control units and protecting them against theft. Even if such an ECU were to be fitted in another identical vehicle, its engine performance characteristics could not be changed: the cryptographic individual key of an ECU has to match all the cryptographic keys within the ECU network of a vehicle. And that key is safely stored in the SHE.

Infineon’s AUDO MAX SHE brings security from the software level to the hardware. Thus, for example, the keystore cannot be read by the diagnostic software and therefore the secret keys are protected particularly well from software attacks. Furthermore, AUDO MAX SHE guards very effectively against any tampering even during boot-up: the secure boot feature ensures that only the original software is loaded during the boot process.

“Our AUDO MAX is a 32-bit microcontroller for powertrain and chassis applications providing very high performance and real-time capabilities. It ranks among the best currently on the market,” said Peter Schaefer, Vice President and General Manager, Microcontrollers, Automotive Division of Infineon Technologies AG. “By incorporating SHE, the AUDO MAX microcontroller provides security in every respect: functional reliability, data integrity and tamper-proofing.”

Availability

The AUDO MAX microcontroller family incorporating SHE currently comprises three products, each with 4 MB flash memory but differing in terms of clock frequency and package: TC1798 (300MHz, BGA-516), TC1793 (270MHz, BGA-416) and TC1791 (240MHz, BGA-292). All are available in sample quantities. Volume production has begun for the TC1793 and is set to begin for the TC1798 and TC1791 from Q1/2012. Infineon’s future 65nm eFlash microcontrollers will offer and significantly extend the SHE functionality with a Hardware Security Module (HSM).